1. Field of the Invention
The present invention relates to measuring systems, and more specifically to a method and apparatus for enhancing the resolution of measurement systems employing image capturing systems to measure lengths.
2. Related Art
Measurement systems often employ image capturing systems to measure various lengths. For example, an image capturing system may provide digital representations of images of an object, and an image processing system (also contained in the measurement system) may process the digital representations to determine the length of the object.
It is often desirable that measurement systems be implemented with a high resolution. As is well known, resolution generally refers to the shortest length (or change therein) a measurement system may detect accurately. For example, a measurement system with a resolution of 1 millimeter (mm) may measure the change of position of an object from 12 mm to 13 mm. Any change in the position of the object less than 1 mm may not be accurately detected by such a measurement system.
Resolution of measurement systems is often limited by the resolution of image capturing systems. For example, a prior image capturing system may be implemented using CCD (charge coupled device) containing several pixels, typically arranged in the form of a matrix. The resolution of such a CCD based system depends on the extent of area of an object captured by each pixel.
The resolution of measurement systems may be enhanced by using higher resolution CCDs (i.e., having more pixels covering a unit area of the image) and/or other optical components (e.g., telescopic lens and magnification lens). However, such components are generally expensive and thus the related implementations are often undesirable.
Accordingly what is needed is a method and apparatus for enhancing the resolution of measurement systems employing image capturing systems to measure lengths while meeting one or more of objectives similar to those described above.